The present invention relates to an electron beam irradiation system and an electron beam irradiation method, which are used, for example, for recording on a master of optical disks.
In recent years, there has been a demand for a higher recording density on optical disks, and, for realizing this, it is necessary to form recording pits more finely.
Therefore, in the manufacture of a master of optical disks, there has been proposed a system of recording by irradiation with an electron beam, with which finer pits can be formed than with a conventional laser light.
In the system of recording by irradiating the master with the electron beam, it is necessary to accurately focus the electron beam on the master for enabling high-precision recording.
Hitherto, as an electron beam irradiation system comprising a means for focusing an electron beam, there has been known the system shown in FIG. 1.
Namely, in this system, a reversing table 41 is provided in a vacuum vessel 40 so that it can be rotated by a reversing mechanism 42, a motor 43 is fixed on one end side of the reversing table 41, a master 45 is mounted on a turn-table 44 fitted to a rotary shaft of the motor 43, and the master 45 is irradiated with an electron beam emitted from an electron beam irradiation means 46 to achieve recording.
In this system, a focusing stage 47 for focusing the electron beam is provided on the other end side of the reversing table 41, namely, at an end portion on the opposite side of the turn-table 44 with respect to the center of rotation of the reversing table 41.
The focusing stage 47 has its upper surface set at the same height with the master 45 mounted on the turn-table 44. At the time of recording on the master 45, first, the focusing stage 47 is made to correspond to the electron beam irradiation means 46, and, in this condition, the upper surface of the focusing stage 47 is irradiated with the electron beam, and focusing of the electron beam is conducted by the electron beam irradiation means 46. Thereafter, the reversing table 41 is rotated 180xc2x0 (reversed) by the reversing mechanism 42 so that the master 45 corresponds to the electron beam irradiation means 46, and the master 45 is irradiated with the electron beam to perform recording.
However, the conventional electron beam irradiation system constituted as above has the following problems.
Namely, the conventional system has a construction such that the master and the focusing stage are moved by reversing, so that the distance between the master and the focusing stage is large, and it is difficult to maintain both of them at the same height accurately.
Therefore, with the conventional system, it is difficult to accurately focus the electron beam on the master, and there is a question as to realization of high-precision recording.
The present invention has been made to solve the above-mentioned problems of the related art. Accordingly, it is an object of the present invention to make it possible to focus an electron beam on a body to be irradiated, for example, a master of optical disks, easily and accurately, and to enable high-precision recording on the master.
In order to attain the above object, the present invention provides an electron beam irradiation system including:
a support mechanism portion having a slide table for supporting a master (a body to be irradiated) to be irradiated with an electron beam so that the master can be rotated and moved in a radial direction, and
an electron beam irradiation means for irradiating the master with the electron beam while partially establishing a vacuum condition on the master, wherein
a focusing stage for focusing the electron beam is stationarily disposed on the slide table of the support mechanism portion at a position adjacent to the master.
In the electron beam irradiation system, focusing of the electron beam is conducted by irradiating the focusing stage with the electron beam before performing recording on the master. Thereafter, the slide table is moved to an electron beam irradiation starting position for the master, and recording is conducted by irradiating the master with the electron beam.
In the electron beam irradiation system according to the present invention, the distance between the master and the focusing stage is short, which is advantageous in view of precision in adjusting the height of the focusing stage to the height of the master. Therefore, it is possible to accurately focus the electron beam on the master and to achieve high-precision recording.
As described above, according to the present invention, the electron beam irradiation system of a partial vacuum system in which only the portion for irradiation with the electron beam is in a vacuum can easily and accurately perform focusing of the electron beam to the body to be irradiated by disposing a focusing stage at a position adjacent to the body to be irradiated on the slide table for supporting the body to be irradiated. Consequently, where the body to be irradiated is a master optical disk, the electron beam irradiation system can perform high-precision recording.
The above and other objects, features and advantages of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings, which show by way of example some preferred embodiments of the invention.